function   Show_Colorimage_ROI(im, roi)

    b   =  roi>0;
    r   =  im(:,:,2);
    mm  =   max(roi(:));
    
    roi(b)  = roi(b)*255/mm;
    roi(~b) = r(~roi);
    im(:,:,2) = roi;
    
    imagesc(im); axis image; axis off; 
end

